Improvement in gas-furnaces



w. L. McNAIR.

GA-S FURNACE.

No.'175',13'1 Patented March 21.183? MAW 61/ 8' e W Y 3 2 h i C 5 i Fig-2 I *1 g e 0 0 i i o L n J- M.

WITNESSE I INVENTUY W if Falw- UNITED STATES PATENT OFFICE.

-WILLIAM L. McNAIE,'oE ALLEGHENY, PENNSYLVANIA.

IMPROVEMENT m GAS-FURNACES.

Specification forming part of Letters Patent No.l76 ,l3 1, dated March 21, 1876; application filed December 23, 1875. i

To all whom it may concern: Be it known that I, WILLIAM L. MGNAIR,

I of Allegheny, in .the county of Allegheny I and State of; Pennsylvania, have invented certain new and useful Improvements in Heating-Furnacei; and I do hereby declarethe follo'wingjto be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being bad to the accompanying drawings, which form part of this specification. I r

, My invention relates to an improvement in heating-furnaces; and it consists in thear tained therein is raised to any degree of' heat that may be desired, and then the products pass down into the llue h underneath the floor i, so as to heat it" from the under side, and

vthus utilize as far as possible heat that would otherwise be wasted. *The heat and products of combustion pass from the flue it into the return flue j up over the bridge 1 into and through the sechnd heating-chamber m. The iron to be heated is first placed in this chamber, vwhere it.is heatedto a cherry-red, and is then transferred to the first chamber e to be still further heated, and thus the two chambers are alternately used on each charge with the exception of the flrst ones. The heatand products of combustion pass from this chain her in downinto the flue a, heating-the floor '0, as already described, then through the return-flue 1' up the stack.

In using this furnace it is designed to use gas as a fuel wherever it can be obtained, and an air-chamber, l, is made over theheatingchamber 6, through which the gas is passed in the pipe 21 down through'the flue 3 in the wall 4 into the ash-pit, and from thence up to the proper burning-place. There may be more than one line through this wall, or the flue maybe built inside of the fiueh, as may be preferred. This gas, in its passage through the flue, is heated to a high degree, so that its combustion gives the most intenseheat. Air is admitted into the chamber 1, where it is heated to a high degree, and from thence it passes down through the flue 5, up through the pipe 6 into. the chamber 7, immediately over the furnace, and from this chamber it is passed through the openings 8, and strikes the burning gases over the bridge 61, so as to cause a perfect combustion. This air is admitted from above, so as to cause a more thorough commingling with the gas, as, the gas is much the' lighter of the two, and would otherwise rise up above the air.

If so desired, the bottom of the chamber 6 may be made concave, and used for puddling iron ormelting steel, instead of simply heating iron, as here described. One air chamber instead of two may be used, if so preferred.

Having thus described my invention, I claim- I .The combination of the gas flue or fines 3, the air-chamber l, flue 5, pipe 6, and chamber 7, substantially as describe In testimony that I claim the foregoing I have hereunto set my hand this 17th day of N ovember, 1875.

WILLIAM L. MoNAIR. Witnesses: RoB'r. M. BARR, F. A. LEHMANN. 

